Stator winding apparatus



1969 R. J. EMINGER 3,460,770

STATOR WINDING APPARATUS Filed Jan. 30. 1967 4 Sheets-Sheet 1 92 90 as $5 82 62 4s ISO I64 29 2 INVENTOR.

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United States Patent O 3,460,770 STATOR WINDING APPARATUS Robert J. Eminger, Fort Wayne, Ind., assignor to Fort Wayne Tool & Die, Inc., Fort Wayne, Ind., a corporation of Indiana Filed Jan. 30, 1967, Ser. No. 612,437 Int. Cl. B65h 81/06 US. Cl. 242-11 11 Claims ABSTRACT OF THE DISCLOSURE An apparatus for converting rotary motion into reciprocal motion which is especially useful in high-speed guntype stator winding machines. Two elongated gun-type winding head assemblies are mounted on a frame. Each of the assemblies has a longitudinal axis and is movable in relation to the frame in the direction of its axis. Two Scotch yokes are mounted on the frame in a manner rendering them also movable in relation to said frame in the direction of the assembly axes. One of the yokes is secured to both assemblies; the other of the yokes is movable independently of the assemblies. A shaft and two cranks are mounted on the frame. Each of the cranks and the shaft are rotatable with respect to the frame. The cranks have separate and spaced-apart axes of rotation. The cranks are operatively connected to the yokes, respectively. The cranks are fixed in relation to the shaft, and are 180 out of identical rotational relation in respect to the shaft. Selective clearances between the assemblies, yokes and frame are provided to allow for any expansion of the yokes in a direction transverse to the assemblies during operation. A barrel cam is positioned between the assemblies and mounted on the frame in a manner allowing the cam to rotate with respect to said frame. The barrel cam is connected to the shaft and to each of the assemblies whereby the rotation of the shaft simultaneously rotates each of the assemblies alternately in opposite directions as the assemblies and yokes reciprocate in the direction of the assembly axes in a manner minimizing vibration and wear due to the expansion of the yokes during operation.

BACKGROUND OF THE INVENTION Field of the invention This invention generally relates to an apparatus for converting rotary motion into reciprocal motion, and more particularly, to a gun-type stator winding apparatus which can be operated at speeds higher than heretofore practicable.

DESCRIPTION OF PRIOR ART Prior gun-type stator winding machines have been limited in speed of operation due in part to the vibration caused by the reciprocating motion of the winding head assemblies. Further limiting the speed of such Winding machines is the expansion of certain parts of the machine which become heated by frictional heat and for which no allowance has been made in the design of the machine. It is therefore highly desirable to provide an improved apparatus for converting rotary motion into reciprocal motion which is especially adapted for gun-type stator winding machines and which has the advantages of minimizing vibration and making allowance for the expansion of certain parts of the machine which are frictionally heated during the operation of the machine.

SUMMARY OF THE INVENTION In the broader aspects of this invention there is provided an apparatus for converting rotary motion into reciprocal motion having a frame and an elongated element mounted on the frame. A counterweight is also mounted on the frame; both said counterweight and the element are movable in relation to the frame in the direction of the longitudinal axis of said element. A shaft and two cranks are mounted to the frame. Each of the cranks and the shaft are rotatable in respect to the frame. The cranks have separate and spaced-apart axes of rotation. The shaft is operatively connected to the cranks, and the cranks are operatively connected to the element and the counterweight, respectively. The cranks have a fixed rotational relation with the shaft and are out of identical rotational relation with the shaft whereby the rotation of the shaft causes the rotation of both of the cranks and the movement of the element said counterweight in opposite directions.

It is therefore the primary object of this invention to provide an improved apparatus for converting rotary motion into reciprocal motion which is especially desirable when used in an improved gun-type stator winding machine.

Another object of this invention is to provide an improved apparatus for converting rotary motion into reciprocal motion which minimizes the vibration caused by the reciprocal motion.

Yet another object of this invention is to provide an improved apparatus for converting rotary motion into reciprocal motion in which a plurality of reciprocating elements are driven by a single rotating shaft in a manner resulting in a minimum of vibration.

Still another object of this invention is to provide an improved apparatus for converting rotary motion into reciprocal motion which makes allowance for the expansion for certain parts of the apparatus which are frictionally heated during the operation of the apparatus.

A further object of this invention is to provide an improved gun-type stator winding machine in which a plurality of winding heads are driven by a single shaft in a manner resulting in a minimum of vibration.

Still further an object of this invention is to provide an improved high speed guntype stator winding machine having a plurality of winding heads driven by a single shaft in which the vibration caused by the reciprocating motion of the winding heads is minimized and which makes allowance for the expansion of certain parts of the apparatus which are frictionally heated during operation, and which also includes a simplified mechanism for rotating each of the winding heads as desired and for connecting the driven shaft to the various winding heads.

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, partially in crosssection, illustrating the entire apparatus of an improved stator winding machine incorporating this invention;

FIG. 2 is a fragmentary and cross-sectional front view of the apparatus illustrated in FIG. 1 taken substantially along the section line 2-2;

FIG. 3 is a cross-sectional view of the apparatus illustrated in FIG. 2 taken substantially along the section line 33;

FIG. 4 is a cross-sectional view of the structure shown in FIG. 2 taken substantially along the section line 4-4;

FIG. 5 is a fragmentary, cross-sectional and greatly exaggerated view of one portion of the apparatus illustrated in FIG. 2 which makes allowance for the expansion of certain parts which are frictionally heated during the operation of the apparatus, taken substantially along the section line 55;

FIGS. 6 and 7 are fragmentary, cross-sectional and greatly exaggerated views of other portions of the structure illustrated in FIG. 2 which combine with the structure of FIG. 5 to make allowance for the expansion of certain parts during the operation, respectively taken substantially along the section lines 66 and 7-7; and

FIG. 8 is a front, cross-sectional view of the apparatus illustrated in FIG. 1 taken substantially along the section line 88.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to the drawings, there is shown a gun-type stator winding machine incorporating the apparatus of this invention. The specific embodiment illustrated in the drawings comprises two winding head assemblies which are operatively connected to a single driving shaft; however, it will become obvious from the description hereinafter that portions of the improved apparatus of this invention including the mechanism which connects and simultaneously rotates the two winding head assemblies and the mechanism which provides allowance for the expansion of certain parts of the apparatus which are frictionally heated during operation is equally applicable to gun-type winding machines having more than two winding assemblies. Further, it will also become obvious from the description following that the improved mechanism which converts rotary motion into reciprocal motion is applicable to machines other than Winding machines and to winding machines having only one or more than two winding head assemblies.

Referring specifically to FIGS. 1 through 4, the ap paratus of this invention is shown to have a rigid box frame 10 having a top 12, a bottom 14, and upstanding sides 16 through 22. Secured to and depending from the top 12 within the confines of the frame 10 is a drive compartment 24. Compartment 24 comprises four compartment sides 28 through 32 which are secured to frame top 12 and are spaced from and generally parallel to frame sides 18 through 22, respectively, and a compartment bottom 26 which extends between the sides 18 through 22 in general parallelism with the frame top 12 and frame bottom 14. Frame 10 also comprises an elongated support and guide element 34 which is positioned midway between and generally parallel to the frame top '12 and frame bottom 14 and is secured to the opposite frame sides 18, 22. Element 34 does not extend to and is spaced apart from frame sides 16, (see FIG. 3).

Mounted on the frame top 12 are two spaced apart winding head assembly guide members 36, 38. Members 36, 38 each have a centrally located bore 44 extending therethrough. Members 36, 38 are respectively positioned in registry with compartment sides 28 and 32 and equally spaced from frame sides 16 and 20. Frame top 12 and compartment sides 28, 32 each have bores 46 therein which are substantially of the same size as bores 44 and are located on the same axis. Element 34 has bores 47 therein on the same axes as bores 46. Bores 47 are substantially larger than bores 46. Secured to the frame bottom 14 and extending on both sides of bottom 14 are two tubular guide members 52, 54. Guide members 52, 54 have interior bores (not shown) substantially the same size as bores 44 and 46 and are positioned on the common axes 56, 58 of bores 44, 46 and 47, and the members 36, 38 and 52, 54. (see FIG. 2).

Positioned in bores 44, 46 and within the members 36, 38 and 52, 54 are two elongated winding head assemblies 48, 50. Winding head assemblies 48, 50 are coaxial of the bores 44, 46 and 47 and members 36, 38 and 52, 54 and are slidably movable therein with respect to frame 10 in both of the opposite axial directions indicated by the arrows 60, 62 of FIG. 2.

Each of the winding head assemblies 48, 50 has secured thereto a winding head 82 having a plurality of needles 80. In relation to the frame 10, the winding heads 82 are respectively secured to an end 79 of assemblies 48, 50 in spaced-apart relation with frame top 12. In the embodiment illustrated in FIG. 1, winding head 82 is provided with four needles 80 and is of the type used to simultaneously wind four-pole stator cores of the type which have poles each comprising a single coil per pole. Both of the assemblies 48, 50 have a bore 68 therein which extends longitudinally of the assemblies the entire length thereof to accommodate wires 78 which respectively feed the various needles 80 of the winding heads 82.

A pair of stator core support assemblies 84 are secured to frame top 12 and respectively surround the members 36, 38 and the winding heads 82 of the assemblies 48, 50. Supports 84 each have a platform 86 which has an opening 88 therein and are spaced apart and parallel to frame top 12. The openings 88 are positioned on axes 56, 58, respectively, and are substantially larger than the bores 44, 46 and 47. Stator cores 90, which are desirably wound, are positioned on the platform 86 coaxial of the axes 56, 58. Openings 88 are large enough to expose the winding slots of the cores 98 such that coils may be wound therein by the winding assemblies 48, 50. Supports 84 have members 92 for holding the cores 90 to platform 86 during the winding operation.

Secured to the winding head assemblies 48, 50 at a position within the frame 10 and between compartment bottom 26 and element 34 is a yoke 94. Yoke 94 comprises a body 96 which is elongated and has a longitudinally extending slot 98 and opposite ears 100 and 102. Slot 98 is defined by a bottom 104 and upstanding sides 106 and extends the entire length of the body 96. Slot 98 has opposite open ends and an open top. Yoke 94 has two pair of bores 108, therein. Bores 110 are centrally positioned of the ear portions 100, 102, respectively, and extend transversely of the longitudinal direction of the yoke 94. Bores 108 are positioned between the bores 110 and extend through the body portion 96 of the yoke 94 and substantially parallel to the bores 110. Yoke 94 is mounted on the frame 10' by means of two guide rods 112, 114. Both guide rods generally extend from the compartment bottom 26 through the element 34 and to the frame bottom 14. Guide rod 114 is secured to both the bottom 26 and the frame bottom 14, and thus, is rigid and stationary. Guide rod 112 is not rigidly secured to the compartment bottom 26, the element 34 or the frame bottom 14. In contrast, slightly elongated openings 116 and 117 are formed in the compartment bottom 26 and in the element 34 as shown, for example, in the greatly exaggerated view of FIG. 5 and in FIG. 2. Secured to the frame bottom 14 is a guide member 118 having a bore 120 which has a cross-sectional shape substantially the same as openings 116, 117. Guide rod 112 is positioned within the openings 116, 117 and bore 120 and is held therein in a manner allowing the rod 112 to move within the bores 116, 120 laterally, but not axially of the assemblies 48, 50 by means of a swing-ball device 122 and an abutment plate 124. Plate 124 is secured to the compartment bottom 26 to cover the opening 116 therein and the ball device 122 is positioned in the bottom of the bore 120 of the guide member 118-. The opposite ends of the rod 112 abut the plate 124 and the 'ball device 122, respectively, so as to be held fast therebetween but still capable of movement laterally of the guide rod 114.

The guides 112, 114 are positioned within the bores 108 of the yoke 94 thus mounting the yoke 94 on the frame 10 in a manner which allows the yoke 94 to move with respect to the frame 10 axially of the guide rods 112, 114 and the assemblies 48, 50.

As afore-mentioned, the yoke 94 is secured to the assemblies 48, 50. This is achieved by providing each assembly 48, 50 with a step-diametered exterior surface and an annular abutment surface 126. The surfaces 126 face away from the winding heads 82 and are positioned in engagement with the respective ears 100, 102 of the yoke 94. Holding the ears 100, 102 in engagement with the surfaces 126 of the assemblies 48, 50 are two annular clamps 128 which are respectively positioned on the assemblies 48, 5t] and secured thereto in engagement with the ears 100, 102. Thus, each of the ears 100, 102 of the yoke 94 is engaged, on opposite sides thereof, respectively, by a surface 126 and by a clamp 128.

For a purpose to be mentioned hereinafter, each of the bores 110 are elongated similarly to the openings 116 as is shown in the highly exaggerated illustrations of FIGS. 6 and 7. At this juncture, it should be stated that only openings 116, 117 and bores 110 and 120 are elongated in the manner above-described and illustrated in FIGS. 5, 6 and 7. All of the other openings and bores in which the assemblies 48, 50' and the guide rods 112 and 114 are positioned are circular in cross-section and only slightly larger than the respective assembly or rod positioned therein so as to hold stationary the respective assemblies or rods and prevent movement therein in a direction lateral to the assemblies 48, 5t) and rods 112, 114.

A yoke 130 is provided and positioned on guide rods 112, 114 beneath the yoke 94 and between the element 34 and the frame bottom 14. Since yoke 130 is similar in many respects to the yoke 94, like reference numerals will be used to identify like parts. Yoke 130', for example, has two bores 108 therein in which guide rods 112, 114 are positioned. Further, yoke 130 has a slot 98 therein which extends longitudinally of the yoke 130. Yoke 130 differs from yoke 94 in that no cars 100, 102 are provided, and the yoke 130 is not attached in any manner to the assemblies 48, 50. However, the yoke 130 has a mass which is substantially identical to the combined mass of the yoke 94 and the assemblies 48, 50. Otherwise, the yoke 130 is substantially identical to the yoke 94. Thus, as above-described, the yoke 130 is movable on the rods 112, 114 independently of the yoke 94 in the direction of the axes 56, 58.

Both the yokes 94, 138' are driven by a common shaft 132 which is driven by a brake motor (not shown) in the conventional manner. Shaft 132 is mounted on and extends through the side 20 of the frame by means of a suitable bearing 134 secured to the side 20. Positioned within the frame 10 and coaxially mounted on the shaft 132 are a crank 136 and a spur gear 138. Gear 138. is positioned on the shaft 132 between the crank 136 and the bearing 134. A pair of substantially identical idler gears 144 are mounted on suitable shafts 148 and mounted by journals 146 on the frame wall 20. The centers of these gears are located on a line 150 drawn through the center of the shaft 132 and substantially parallel to and equally spaced from the winding head assemblies 48, 50. Gears 144 are further positioned on opposite sides of the shaft 132 and in mesh with gear 138 which is secured to the shaft 132. Thus mounted, the line 150' extends through the centers of each of the shafts 132 and 148.

A second crank 136a is mounted on the wall by means of a suitable shaft 152 and a suitable bearing 154. Secured to the shaft 152 is a spur gear 155 between the crank 136a and the bearing 154. The shaft 152 is positioned beneath the shaft 132 and in spaced-apart and parallel relation therewith; and thus, the cranks 136, 136:: have separate axes of rotation which are spaced apart and parallel to each other. Further, the center of the shaft 152 is positioned on the line 150 and the gear 155 is both coaxial of the shaft 152 and is connected to the gear 138 by means of the idler gear 144 located therebetween. Thus, the centers of each of the gears 138, 144 and 155 are positioned on the line 150. Further, as shown in FIG. 1, each of these gears are also aligned one over the other such that the end surfaces of the gears are in common planes which are substantially parallel to the axes 56, 58 and are adjacent to the frame side 20.

Both the cranks 136, 136a have a crank pin 156 secured to the crank adjacent to the periphery thereof. Each crank pin 156 is spaced-apart from and substantially parallel to the axis about which the respective crank rotates. A roller 158 is journalled on each of the crank pins 156 so as to be rotatable about the crank pins 156 independently of the cranks 136, 136a. The rollers 158 are positioned within the slots 98 of the respective yokes 94, afore-described. By this means, the cranks operatively connect the yokes 94, 130 to the shaft 132.

Each of the cranks 136, 136a has a fixed rotational relationship with the drive shaft 132. Crank 136 is secured directly to the drive shaft 132 such that as the drive shaft 132 rotates so does the crank 136. Crank 136a, on the other hand, is connected to the drive shaft 132 by means of the gears 138, and the idler gear 144. Each of these gears is chosen to have an appropriate number of teeth and size such that the crank 136a also rotates at the same speed as the shaft 132. However, as shown in FIG. 1, each of the cranks are positioned 180 degrees out of identical rotational relation with the shaft 132. In other words, when the crank pin 156 of crank 136 is positioned at the topmost position, the crank pin 156 of the crank 136a is positioned at the bottom-most position.

Mounted within the drive compartment 24 is a barrel cam 160. Barrel cam 160 is secured by a key 161 to a shaft 162 which is appropriately journaled at 164 and 166, respectively, and secured to the compartment sides 29, 30. Barrel cam 160 is also equally spaced from compartment sides 28, 32; and thus, is equally spaced from the winding head assemblies 48, 50. Secured to the barrel cam 160 is a drive gear 170. Gear is connected to the gear 138 by means of the idler gear 144 located therebetween. Thus, rotation of shaft 132 also rotates the cam 160. Further, the gears 170, 144 and 138 are chosen with the appropriate number of teeth and size that one revolution of the shaft 132 equals one revolution of the barrel cam 160.

Cam 160 has an annular cam track or groove 172 therein. Groove 172 is defined by a bottom 174 and upstanding side walls 176. Groove 172 is continuous and extends completely around the circumference of the earn 160. Bottom 174 of the groove 172 is at all points substantially parallel to the exterior surface of the cam 160 and the oppositely facing side walls 176 are substantially parallel to each other. However, the side walls 176 have certain undulations 178 therein as indicated in FIGS. 1 and 4.

Also mounted within the drive compartment 24 are two cam followers 180. Since each of these cam followers 180 and the means by which they are mounted within the compartment 24 are identical the description of one will sufiice for both of them. Cam followers 180 each have a body portion 182, a rack 184 and a cam-engaging portion 186, both of which are secured to the body 182. Body 182 has two bores 188 extending therethrough in a direction generally parallel to the longitudinal direction of the rack 184. BOres 188 are generally parallel to each other. The cam followers 180 are each mounted on the frame 10 within the compartment 24 by means of two guide rods 190 and 192. Rods 190, 192 are respectively positioned within the bores 188 and are secured adjacent their opposite ends to the sides 29, 30 of the drive compartment 24. Guide rods 190 and 192 are substantially parallel to each other and parallel to shaft 162 of the barrel cam 160. Further, the guide rods 190, 192 are spaced apart from the shaft 162 a distance such that when the follower 180 is positioned on the rods, the cam engaging portion 186 of the follower 180 is positioned within the groove 172. Thus positioned, as the barrel cam 160 rotates the cam followers 180 slide axially on the rods 190, 192 in response to the undulations 178 of the groove 172 of the barrel cam 160.

The sides 28, 32 of the drive compartment 24 are provided with slots 200 therein. The rack portion 184 of the cam follower 180 fits in the slot 200 and the slot 280 accommodates the above-described movement of the cam follower 180. Slot 200 faces inwardly of the compartment 24 and communicates with a bore 202 which is coaxial of and substantially larger than the bore 46. Both the slots 200 and the bores 202 have a dimension in the direction of the axes 56, 58 only slightly larger than the transverse dimension of the rack 184. Positioned within the bore 202 is a gear 204 which is in mesh with the rack 184. The gears 204 are positioned on the assemblies 48, 50, respectively. The assemblies 48, 50 in the portion between the annular surface 126 and the winding heads 82 are splined adjacent to the surfaces 126. The gears 204 are positioned on this splined portion of the assemblies 48, 50 and are in mesh therewith such that the gears 204 cannot rotate independently of the assemblies 48, 50. On the other hand, because of the splined portion of the assemblies 48, 50, the assemblies 48, 50 can move reciprocally in the opposite directions indicated by the arrows 60, 62 in relation to the gears 204. The splined portion of the assemblies 48, 50 is referred to generally by the reference numeral 206 in FIG. 2. This portion only need be long enough in the direction of the axes 56, 58 in order to insure that the gear 204 will stay in mesh with such a portion during the reciprocal motion of the winding head assemblies 48, 50.

In operation, the structure above-described of this invention functions to simultaneously move the Winding heads 82 of the assemblies 48, 50 reciprocally through the bore of the stator core 90 to be wound and also to rotate the heads 82 adjacent to the opposite ends of the reciprocal stroke. This motion is conventional with guntype stator winding machines. Movement of the head 82 with its wire dispensing needles 80 through the stator core 90 in one direction carries the wires 78 (one wire for each needle 80) therethrough to form one side of a coil. The head 82 is then rotated a part revolution at the end of the stroke to form one end turn of the coil; then, the head 82 is moved in the opposite axial direction back through the core 90 to form the other side of the coil; and then, the head 82 is rotated in the opposite direction back to its original rotational position thus completing the cycle, and one complete turn for each of the needles 80. Both winding head assemblies 48, 50 undergo this movement simultaneously and at a relatively high speed. For example, in one embodiment, the assemblies 48, 50 each complete 1800 of the cycles above-described per minute. Thus, 1800 turns of the stator are wound by each of the needles 80 of the assemblies 48, 50 during each minute of operation.

Each of the winding head assemblies 48, 50 are driven by a common drive shaft 132. Shaft 132 being driven by a brake-motor (not shown) rotates both the gear 138 and the crank 136 which are secured to the shaft 132. As will become obvious from the description hereinafter, the shaft 132 is rotated at a speed, measured in r.p.m. which is identical to the desired speed of the winding head assemblies 48, 50, measured in cycles or turns per minute. The rotation of the shaft 132 by means of the idler gears 144 also rotates the shaft 152 and the barrel cam 160 at the same speed. Thus, both of the cranks 136, 136a and the barrel cam 160 rotate at the same speed; and a single rotation of the shaft 132 will rotate the barrel cam one complete revolution and will move both assemblies 48, 50 through one cycle of movement.

The assemblies 48, 50 are moved through each cycle in the following manner. As the shaft 132 rotates the crank 136 attached thereto rotates to move the yoke 94 upwardly. Since both assemblies 48, 50 are secured to the yoke 94 the assemblies also move upwardly. When the crank pin 156 is at the top-most position, the assemblies 48, 50 are at their top-most position. At this position, the cam engaging porton 186 of the cam follower 180 engage an undulation 178 of the slot 172 of the barrel cam 160 so as to move the cam followers 180 axially of the rods 190, 192 so as to rotate the assemblies 48, 50 in one direction a part revolution. The crank 136 continues rotating moving the yoke 94 and the assemblies 48, 50 downwardly into the lower-most position. At thi moment, the cam engaging portions 186 of the cam followers 180 engage another undulation 178 of the slot 172 of the barrel cam to move the cam followers in the opposite axial direction of the rods 190, 192 so as to rotate the assemblies 48, 50 back to their initial rotational position and the cycle is started all over again.

While the specific embodiment illustrated in the drawings and above described have the cranks 136, 136a and the barrel cam 160 rotating at the same speed, obviously this is not essential to the operation of the structure and could be modified. For example, the barrel cam 160 could be rotated at a speed one-half that of the crank 136 if the groove 172 had twice as many undulations 178 to move the cam followers 180. Other such modifications to the speed of the crank 136 and the barrel cam 160 could also be made.

In prior gun-type winding machines having winding head assemblies such as 48, 50 reciprocally moving, considerable vibration is experienced. Such vibration is minimized by the structure of this invention; and more specfically, by the provision of the yoke 130. As above-described the rotation of the shaft 132 rotates both cranks 136, 136a at the same speed. The rotation of the crank 136a reciprocally moves the yoke 130 axially of the guide rods 112, 114 at the same time as the yoke 94 is similarly moving; and both yokes 94, 130 move at the same speed. However, the cranks 136, 136a are 180 degrees out of identical rotational relationship with the shaft 132. This fixed rotational relationship of the cranks 136, 136a to the shaft 132 and to each other provides that when a yoke 94 moves, the yoke 130 moves in the opposite direction. Thus, when the yoke 94 moves upwardly, the yoke 130 moves downwardly at the same speed and vice versa. Further, since as above-mentioned, the yoke 130 is provided with a mass substantially the same as the combined mass of the yoke 94 and the winding head assemblies 48, 50, momentum of the yoke 94 and the assemblies 48, 50 is always balanced by the momentum of the yoke 130. Or, in other words, the product of the combined mass of the yoke 94 and the assemblies 48, 50 and the velocity at which they are traveling is at all times equal to and in an opposite direction of the product of the mass of the yoke 13!) and its velocity.

Obviously, the mechanism of this counter balancing portion of the apparatus above described could be modified in several respects. For example, the combined mass of the yoke 94 and the assemblies 48, 50 would not necessarily need to be substantially the same as the mass of the yoke 130 so long as the product of the combined mass times the velocity of the yoke 94 and the assemblies 48, 50 is kept equal to the product of the mass of the yoke 130 times its velocity. Thus, for example, the yoke 130 could have a mass one-half of that of the combined mass of the yoke 94 and the assemblies 48, 50 so long as the crank pin 156 of the crank 136a was spaced from the axis of rotation of the crank 136a one-half the distance between the axis of rotation of the crank 136 and its crank pin 156. Other modifications in the weight of the mass of the yokes and the positioning of the crank pins 156 from the axes of rotation of the cranks 136, 136a could be made; however, in each of these different embodiments, both of the cranks 136 must rotate at the same speed.

A further limitation to high speed operation of prior art gun-type winding machines has been the expansion of certain parts of the machine which become heated by frictional heat due to the high speed operation and for which no allowance has been made in the design of the machine. The apparatus above-described make such allowance by providing that the bores 110, 120 and the openings 116 and 117 in the yoke 94, the guide member 118, the bottom 26 of the drive compartment 24 and guide element 34 are out-of-round and elongated in the specific direction shown by the exaggerated drawing of FIGS. 5 through 7. This structure allows for the lateral expansion of the yokes 94 and 130. These yokes, because of their mass and high speed movement along the guide rods 112, 114 are the two parts of the assembly abovedescribed which cause an expansion problem at the speed that the above structure is operated. Thus, allowing for the lateral expansion of the yokes 94, 130 during operation solves the expansion problem. By means of the elongated bores 110 and 120 and the openings 116, 117, the guide rod 112 is moved away from the guide rod 114 in a direction of a line drawn perpendicular to and through the centers of the rods 112 and 114. Thus, when the body portion 96 of the yokes 94 and 130 expand, the guide rods are adapted to move laterally apart accommodating for this expansion. Further, by the elongation of the bores 110 in the same direction, the expansion of the yoke 94 adjacent to the ears 100 and 102 is also accommodated. Thus, the expansion of the yokes 94 and 130 does not cause any binding between the yokes, the assemblies 48, 50 and the guide rods 112, 114 during the operation of the apparatus.

The apparatus of this invention, while above-described in relation to a gun-type stator winding machine, is capable of wide application for converting rotary motion into reciprocal motion. In this wide application the structure which minimizes the vibration caused by the reciprocal motion and the structure which makes allowance for the expansion of the yokes 94, 130 due to the frictional heating thereof are also widely applicable. Further, however, the structure is uniquely applicable to gun-type stator winding machines and allows high speed operation thereof. The unique drive means by which each of the yokes 94, 130 and the barrel cam 160 is driven by a common shaft 132 and the means by which the assemblies 48, 50 are rotationally actuated by a single barrel cam 160 are also uniquely applicable to winding machines. This structure provides a structure simple in construction for driving multiple winding head assemblies 48, 50 by a common shaft 132. This same structure is applicable to winding machines having more than two winding head assemblies 48, 50, for example, by merely elongating the yoke 94 to accommodate any number of winding head assemblies in two parallel rows extending on opposite sides of an elongated barrel cam, the same structure could be used to actuate a plurality of winding head assemblies 48, 50.

While there have been described above the principles of this invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention.

What is claimed is:

1. A stator winding apparatus comprising a frame, a first elongated gun-type winding head assembly having a first longitudinal axis, means for mounting said first assembly on said frame for movement in the direction of said first axis, a second elongated gun-type winding head assembly having a second longitudinal axis in spaced, parallel relationship with said first axis, means for mounting said second assembly on said frame for movement in the direction of said second axis, a yoke, means for drivingly securing said yoke to said first and second assemblies, means for mounting said yoke on said frame for movement in the direction of said axes, a shaft and first and second cranks, means for rotatably mounting each of said cranks and shaft on said frame, said cranks respectively having separate and spaced apart axes of rotation, means for drivingly connecting both of said cranks to said shaft, said cranks each having a crank pin respectively spaced from said axes of rotation, a counterweight, said yoke having a slot therein extending transversely of said first and second assemblies, said crank pin of said first crank being positioned in said slot, said crank pin of said second crank being operatively connected to said counterweight, said cranks having a fixed rotational relation with said shaft, said crank pins being substantially out of identical rotational relation with said shaft, a barrel cam, means for rotatably mounting said barrel cam on said frame between said assemblies, means for drivingly connecting said barrel cam to said shaft, first and second cam, followers respectively operatively connected to said barrel cam on opposite sides thereof, means for mounting said first cam follower on said frame for slidable movement with respect to said frame and said first assembly transversely of said first assembly, a first rack secured to said first cam follower, means for mounting said second cam follower on said frame for slidable movement with respect to said frame and said second assembly transversely of said second assembly, a second rack secured to said second cam follower, each of said assemblies including a splined rod portion and a gear positioned on said rod portion, said gear mating with said rod portion whereby said gears are prevented from rotating independently of said rod portion, said rod portion being slidably movable in said gear in the direction of said assembly axis, said gears being respectively operatively geared to said first and second racks whereby the rotation of said shaft moves said cam followers in reciprocal motion thereby respectively rotating said assemblies alternately in opposite directions as said assemblies reciprocate in the direction of said axes.

2. A stator winding apparatus comprising a frame, two elongated gun-type winding head assemblies each having a longitudinal axis, means for respectively mounting each of said assemblies on said frame for movement in the direction of said axes, first and second yokes, means for respectively mounting said yokes on said frame for independent movement in the direction of said axes, means for drivingly securing said first yoke to both of said assemblies, a shaft and first and second cranks, means for rotatably mounting said cranks and shaft on said frame, said cranks having separate axes of rotation, means for operatively connecting both of said cranks to said shaft, each of said cranks having a crank pin respectively spaced from said axes of rotation, said crank pins being operatively connected to said yokes, respectively, said crank pins being substantially 180 out of identical rotational relation with said shaft, said cranks.

having a fixed rotational relation with said shaft, whereby the rotation of said shaft causes the rotation of both of said cranks and the movement of said yokes axially of said assemblies in opposite directions, said first yoke having means respectively providing expansion clearance with said assemblies, said frame also having means for cooperating with said last-named means, to allow for expansion of said yokes in a direction transverse to said axes.

3. The stator winding apparatus of claim 2 wherein said frame has two spaced apart guide rods disposed substantially parallel to each other and to said assemblies, said first and second yokes each having two spaced apart apertures therein, said guide rods being positioned in said apertures respectively, said yokes being slidably movable axially of said rods, and wherein said cooperating means comprises means on said frame providing an expansion clearance between one of said guide rods and said frame, said last-named clearance extending in a direction transverse to said one guide rod and away from the other of said guide rods.

4. The stator winding apparatus of claim 3 wherein said first yoke has a second pair of spaced apart apertures therein, said assemblies being positioned in said second apertures, said second apertures being enlarged in the direction of a line drawn transversely of and intersecting the axes of said assemblies, said apertures providing an expansion clearance located intermediate said assemblies when said first yoke is at an ambient temperature.

5. The stator winding apparatus of claim 2 further comprising a barrel cam and two cooperating cam foll it lowers, means for rotatably mounting said barrel cam on said frame, means for operatively connecting said barrel cam to said shaft, means for mounting said cam followers on said frame on opposite sides of said barrel cam for slidable movement with respect to said frame and said assemblies, said assemblies each including a splined rod portion and a gear positioned on said rod portions, said gears respectively mating with said rod portions whereby said gears are respectively prevented from rotating independently of said rod portions, said rod portions being respectively slidably movable in said gears in the directions of said axes, two racks respectively secured to said cam followers, said gears respectively being operatively geared to said racks whereby the rotation of said shaft moves said followers in reciprocal motion thereby simultaneously rotating each of said assemblies alternately in opposite directions as said assemblies reciprocate in the direction of said axes.

6. The stator winding apparatus of claim 5 wherein said frame has two spaced apart guide rods disposed substantially parallel to each other and to said assemblies, said first and second yokes each having two spaced apart apertures therein, said guide rods being positioned in said apertures respectively, said yokes being slidably movable axially of said rods, and wherein said cooperating means comprises means on said frame providing an expansion clearance between one of said guide rods and said frame, said clearance extending in a direction transverse to said one guide rod and away from the other of said guide rods.

7. The stator winding apparatus of claim 6 wherein said first yoke has a second pair of spaced apart apertures therein, said assemblies being positioned in said second apertures, abutting members secured to both of said assemblies on opposite sides of said first yoke thereby securing said first yoks to said assemblies, said second apertures being enlarged in the direction of a line drawn transversely of and intersecting the axes of said assemblies, said second apertures providing an expansion clearance located intermediate said assemblies when said first yoke is at an ambient temperature.

8. The stator winding apparatus of claim 7 wherein said assemblies and first yoke have a combined mass substantially equal to the product of the mass of said second yoke the ratio of the velocity of said second yoke to the velocity of said assemblies in the direction of said axis.

97 The stator winding apparatus of claim 8 wherein said shaft and one of said cranks are positioned on the same axis and have the same axis of revolution, said one crank being secured to said shaft; and further comprising a first gear coaxially secured to said shaft, a second gear positioned on the same axis as said other crank and being secured to said other crank, said first and second gears having respectively the same axes of revolution as said shaft and other crank, and a third gear operatively coupling said first and second gears.

10. An apparatus comprising a frame, two spacedapart and parallel elongated guide rods connected to said frame, a member having two spaced-apart bores therein, said rods being positioned in said bores thereby mounting said member to said frame, said member being movable in relation to said frame in the longitudinal direction of said rods, one of said rods being secured to said frame, first means for permitting the other of said rods to move toward and away from said one rod in a direction transverse thereto, and second means for reciprocally driving said member in the longitudinal direction of said rods.

11. The apparatus of claim 10 further comprising an elongated element mounted to said frame, said element being movable with respect to said frame in the longitudinal direction of said rods, said element being drivingly secured to said member; and wherein said first means includes openings in said frame and said member which are elongated in the direction of a line drawn transversely of said rods.

References Cited UNITED STATES PATENTS 2,501,631 3/1950 Oschwald 74-50 2,949,789 8/1960 Eminger 242 1.1 3,205,722 9/1965 Happe 74-50 3,276,275 10/1966 Ebbert 242-11 BILLY S. TAYLOR, Primary Examiner U.S. Cl. X.R. 74S0 

